A Simple Proposal for Including Designer Preferences in Multi-Objective Optimization Problems

[EN] Including designer preferences in every phase of the resolution of a multi-objective optimization problem is a fundamental issue to achieve a good quality in the final solution. To consider preferences, the proposal of this paper is based on the definition of what we call a preference basis that shows the preferred optimization directions in the objective space. Associated to this preference basis a new basis in the objective space-dominance basis-is computed. With this new basis the meaning of dominance is reinterpreted to include the designer's preferences. In this paper, we show the effect of changing the geometric properties of the underlying structure of the Euclidean objective space by including preferences. This way of incorporating preferences is very simple and can be used in two ways: by redefining the optimization problem and/or in the decision-making phase. The approach can be used with any multi-objective optimization algorithm. An advantage of including preferences in the optimization process is that the solutions obtained are focused on the region of interest to the designer and the number of solutions is reduced, which facilitates the interpretation and analysis of the results. The article shows an example of the use of the preference basis and its associated dominance basis in the reformulation of the optimization problem, as well as in the decision-making phase.This work has been supported by the Ministerio de Ciencia, Innovacion y Universidades, Spain, under Grant RTI2018-096904-B-I00.Blasco, X.; Reynoso Meza, G.; Sánchez Pérez, EA.; Sánchez Pérez, JV.; Jonard Pérez, N. (2021). A Simple Proposal for Including Designer Preferences in Multi-Objective Optimization Problems. Mathematics. 9(9):1-19. https://doi.org/10.3390/math90909911199

Asymmetric distances to improve n-dimensional Pareto fronts graphical analysis

isualization tools and techniques to analyze n-dimensional Pareto fronts are valuable for designers and decision makers in order to analyze straightness and drawbacks among design alternatives. Their usefulness is twofold: on the one hand, they provide a practical framework to the decision maker in order to select the preferable solution to be imple- mented; on the other hand, they may improve the decision maker s design insight,i.e. increasing the designer s knowledge on the multi-objective problem at hand. In this work, an order based asymmetric topology for finite dimensional spaces is introduced. This asymmetric topology, associated to what we called asymmetric distance, provides a theoretical and interpretable framework to analyze design alternatives for n-dimensional Pareto fronts. The use of this asymmetric distance will allow a new way to gather dominance and relative distance together. This property can be exploited inside interactive visualization tools. Additionally, a composed norm based on asymmetric distance has been developed. The composed norm allows a fast visualization of designer preferences hypercubes when Level Diagram visualization is used for multidimensional Pareto front analysis. All these proposals are evaluated and validated through different engineering benchmarks; the presented results show the usefulness of this asymmetric topology to improve visualization interpretability.This work was partially supported by EVO-CONTROL project (ref. PROMETEO/2012/028, Generalitat Valenciana - Spain) and the National Council of Scientific and Technologic Development of Brazil (CNPq) with the postdoctoral fellowship BJT-304804/2014-2.Blasco Ferragud, FX.; Reynoso Meza, G.; Sánchez Pérez, EA.; Sánchez Pérez, JV. (2016). Asymmetric distances to improve n-dimensional Pareto fronts graphical analysis. Information Sciences. 340:228-249. doi:10.1016/j.ins.2015.12.039S22824934

Antiurolithic activity of Berberis trifoliate extract on induced urolithiasis in rats by zinc disc implantation

Background: In clinical therapy, there is no satisfactory drug available for treatment of urolithiasis, especially for the prevention of their recurrence. The aim of this work was to evaluate in vivo antiurolithic activity of methanolic extract of Berberis trifoliata leaves.Material and methods: Urolithiasis was induced in Wistar rats by zinc disc implantation in urinary bladder. Upon postsurgical recovery, different doses of the methanolic extract of B. trifoliata leaves (50, 100 and 150 mg/kg body weight) were administered orally to zinc disc implanted rats for a period of 20 days. Antiurolithiatic activity was evaluated by measuring the difference between the weight of the implanted zinc discs at the time of implantation and the final weight of the dried calculi taken out from the bladder at the end of the 20 days period of treatment.Results: Extract of B. trifoliata significantly reduced calculi deposition around the implanted zinc disc at all doses (50, 100, and 150 mg/kg).Conclusion: Treatment with methanolic extract of B. trifoliata is useful agent against the kidney stone formation.Keywords: Antiurolithic, Berberis trifoliata, urolithiasis, zinc disc implantation

Proceso de descolonización, el rol de los intereses económicos, políticos, jurídicos de España y Marruecos: caso Sahara Occidental. Período de 2010-2018

El conflicto del Sahara Occidental se ha caracterizado particularmente en un fenómeno transcendente con repercusiones de enorme envergadura en la política mundial contemporánea. Después del periodo de la guerra fría retomar el caso de descolonización del pueblo saharaui sigue siendo hasta hoy 2019 un desafío único en vista de las raíces históricas del mismo y los diversos actores que definitivamente tienen la capacidad de moldear el punto de estancamiento en el que se encuentran, hacia una paz urgente de voluntades políticas en la Organización de Naciones Unidas. Categóricamente España y Marruecos cómplices en la ocupación del territorio del Sahara Occidental difieren tácitamente de la normativa internacional y los procedimientos probatorios de ilegalidad. Sin embargo, entender los intereses económicos y geopolíticos de las potencias en la región del Magreb explica el empoderamiento de dicho territorio. La existencia de los recursos naturales como el fosfato, la pesca, yacimientos de petróleo y gas son una realidad dentro de los límites geográficos del Sahara, por lo tanto el juego político supone una compleja irregularidad en la dinámica teórica del conflicto. Demostrar las aristas enfocadas a una solución viable convierte este caso en un reto para la Comunidad Internacional, lo que implica un debate profundo en el marco de las relaciones internacionales y su finalidad de manejar este asunto al más alto nivel diplomático y polític

CONUT: A Useful Alarm of Malnutrition in the Centralized Laboratory of a Spanish Hospital

Background: Hospital malnutrition, usually secondary to various diseases and their treatments, is an important problem in our clinical practice. For its proper assessment, it is crucial to use a nutritional alert system, such as the CONUT (COntrol NUTrition) program; this tool uses 3 analytical parameters: serum albumin, total cholesterol, and total lymphocyte count. Objective: The current study assessed the results of the implementation of this program in the University Hospital Ramón y Cajal. Methods: The CONUT program has been used in the University Hospital Ramón y Cajal since 2013. This retrospective study, throughout 2016, was conducted in the Central Laboratory of Chemical Biochemistry at the University Hospital Ramón y Cajal. All blood tests with serum albumin, total cholesterol, and total lymphocyte count were studied. The degree of malnutrition was assessed using the scale of normal (=0), mild (=4), moderate (=8), and severe (=12). Results: In 2016, there were 405406 analytics performed in the laboratory of University Hospital Ramón y Cajal. The CONUT tool was applied to 3.64% of them (14741 analytics). In the outpatient setting, the highest malnutrition index comprised patients from the liver transplant consultation department, followed by the cardiology, rheumatology, and oncology departments. With inpatients, the hematology, cardiology, and endocrinology departments showed the most severe malnutrition index. Conclusion: The CONUT system seemed to provide useful information about the cohort of the studied hospital. The results showed that 94% of the patients were not classified with malnutrition, there was no gender predilection, and they were younger than the rest. Patients with more severe malnutrition were usually older and male

Nonconventional Wastewater Treatment for the Degradation of Fuel Oxygenated (MTBE, ETBE, and TAME)

Catalytic wet air oxidation (CWAO) is a nonconventional wastewater treatment, consisting of oxygen pressure releasing inside a reactor in order to degrade organic compounds dissolved in water, using a solid catalyst in the presence of an activated O2 species, usually at temperatures ranges of 125–250°C and pressures of 10–50 bar. CWAO can reduce operating costs of conventional treatment due to the use of ideal catalyst that is able to improve reaction conditions at temperatures and pressures as mild as possible, simultaneously setting high catalytic activity and long-term stability of heterogeneous catalysts. Oxygenated fuels are gasoline additives in reformulated gasoline and oxyfuels. In the beginning, they provided an alternative solution of environmental problems, such as greenhouse gas emissions and octane enhancement, caused by fossil fuel use. The oxygenated fuels frequently used are methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME). However, there is environmental impact from oxygenated fuel hydrocarbons related to widespread contamination of groundwater and other natural waters. Our research group developed a wide study in order to evaluate several catalysts (Ru, Au, Cu, and Ag supported on Al2O3, Al2O3-CeO2, and TiO2-CeO2) and to obtain the best for the efficiency of the oxidation process

Efecto de la temperatura del medio de enfriamiento por temple sobre las propiedades mecánicas de la aleación TiAl

Se analizaron las propiedades mecánicas sobre muestras de una aleación TiAl que fue solubilizada a 1100°C y enfriada en una aleación fundida o baño metálico con una composición Sn-21Bi estabilizado a tres diferentes temperaturas. Así mismo se analizó el cambio microestructural de la aleación y se evaluaron las propiedades mecánicas que dicho tratamiento generó, realizando ensayos de dureza y compresión, dicho tratamiento logró elevar la dureza hasta 4 veces en relación a la probeta testigo. Sin embargo, la mejor relación entre dureza y tenacidad se logra cuando solo se duplica la dureza y se conserva una buena tenacidad en el ensayo de compresión, esto debido a una microestructura mixta y con un porcentaje de fases alfa-beta equitativo. Esta microestructura es producto de las condiciones específicas durante el enfriamiento, con lo cual se demuestra que no solo hay una relación entre las propiedades mecánicas entre el material y su microestructura, sino también depende del porcentaje de fases presentes.Mechanical properties were analyzed on samples of a TiAl alloy that was solubilized at 1100°C and cooled in a molten alloy or metal bath with a Sn-21Bi composition stabilized at three different temperatures. The microstructural change of the alloy was analyzed and the mechanical properties that said treatment generated were evaluated, performing hardness and compression tests. The metalic bath treatment managed to raise the hardness up to 4 times in relation to the control specimen. However, the best relationship between hardness and toughness is achieved when only the hardness is doubled and a good toughness is retained in the compression test, this due to a mixed microstructure with a percentage of equitable alpha-beta phases. This microstructure is a product of the specific conditions during cooling, which demonstrates that there is not only a relationship between the mechanical properties and its microstructure, but also depends on the percentage of phases present

Caracterización metalúrgica del acero SA-612 deteriorado después de quince años de servicio

Se analizó el deterioro en tanque estacionario para gas LP de acero SA-612 después de quince años de servicio, mediante un análisis microestructural en el Microscopio Electrónico de Barrido (MEB), ensayos de impacto Charpy, tensión uniaxial y dureza Rockwell C. Se encontró que la resistencia máxima a tensión y dureza disminuyeron 15 y 36%, respectivamente, mientras que la elongación incrementó del 16 al 40%, con respecto a propiedades originales. De la caracterización microestructural se observó que el acero está deteriorado con reducción en la cantidad de perlita y precipitación de partículas en límites de grano ferritico con tamaño grande debido a la exposición en intemperie. Por lo tanto, este tanque mostro degradación microestructural y mecánica en tensión e impacto, es decir, presento una condición de sobre-envejecimiento, a causa de las condiciones de servicio, favoreciendo posibles fugas de gas y explosiones catastróficas.The deterioration in stationary tank for SA-612 steel LP gas after fifteen years of service was analyzed by microstructural analysis in the Scanning Electron Microscope (SEM), Charpy impact tests, uniaxial tension and Rockwell C hardness. It was found that the ultimate tensile strength and hardness decreased 15 and 36%, respectively, while the elongation increased from 16 to 40%, with respect to original properties. From the microstructural characterization, it was observed that the Steel is deteriorated with a reduction in the amount of pearlite and precipitation of particles in limits of ferritic grain with large size due to exposure in the outdoor. Therefore, this tank showed microstructural and mechanical degradation under tension and impact, that is, it presented an over-aging condition, due to the service conditions, favoring possible gas leaks and catastrophic explosions

Generación de energía mediante una bomba funcionando como turbina en una conducción de abastecimiento de agua de Guanajuato

[EN] In this work the characteristic curve of the operation of a pump as a turbine is obtained to calculate the energy that can be generated in a gravity pipeline from two dams to a drinking water treatment plant for water supply, which is supplied with a variable flow depending on consumption in the city of Guanajuato, Mexico. The characteristic curve is obtained by means of empirical formulas and experimental curves of pumps proposed by different authors, which predict the operation of the pump operating as a turbine. The formulas are used to determine the optimum operating point at which the machine can work, by means of the variables: flow rate, hydraulic head, and efficiency. In this case, the energy generated by the pump operating as a turbine is 90 626.35 kWh/year.[ES] En el presente trabajo se obtiene la curva característica del funcionamiento de una bomba como turbina para calcular la energía que se puede generar en una conducción por gravedad desde dos presas hasta una planta de tratamiento de agua potable para abastecimiento de agua, la cual es suministrada con un caudal variable en función del consumo y se encuentra ubicada en la ciudad de Guanajuato, México. La curva característica se obtiene por medio de fórmulas empíricas y curvas experimentales de bombas propuestas por diversos autores, las cuales predicen el funcionamiento de la bomba operando como turbina. Las fórmulas se utilizan para conocer el punto de funcionamiento óptimo en el que puede trabajar la máquina, mediante las variables: caudal, carga hidráulica y eficiencia. Finalmente, en el caso de estudio, la energía generada por la bomba funcionando como turbina es de 90 626.35 kWh/año.Joaquín Cuarenta, JD.; Mora-Rodríguez, J.; Carreño Aguilera, G.; Ortiz Medel, J.; Pérez-Sánchez, M.; López Jiménez, PA. (2019). Generation of energy from a pump functioning as a turbine in a main of water supply of Guanajuato. Acta Universitaria (Online). 29:1-14. https://doi.org/10.15174/au.2019.2512S1142

ANTIUROLITHIC ACTIVITY OF BERBERIS TRIFOLIATA EXTRACT ON INDUCED UROLITHIASIS IN RATS BY ZINC DISC IMPLANTATION

Background: In clinical therapy, there is no satisfactory drug available for treatment of urolithiasis, especially for the prevention of their recurrence. The aim of this work was to evaluate in vivo antiurolithic activity of methanolic extract of Berberis trifoliata leaves. Material and methods: Urolithiasis was induced in Wistar rats by zinc disc implantation in urinary bladder. Upon postsurgical recovery, different doses of the methanolic extract of B. trifoliata leaves (50, 100 and 150 mg/kg body weight) were administered orally to zinc disc implanted rats for a period of 20 days. Antiurolithiatic activity was evaluated by measuring the difference between the weight of the implanted zinc discs at the time of implantation and the final weight of the dried calculi taken out from the bladder at the end of the 20 days period of treatment. Results: Extract of B. trifoliata significantly reduced calculi deposition around the implanted zinc disc at all doses (50, 100, and 150 mg/kg). Conclusion: Treatment with methanolic extract of B. trifoliata is useful agent against the kidney stone formation